Nanotechnology Project

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Environment, Health and Safety Research

Solubilization of carbon nanotubes and fullerenes in natural waters under environmental conditions

Project Information

Principal InvestigatorB. Nowack
Project URLView
Relevance to ImplicationsHigh
Class of NanomaterialEngineered Nanomaterials
Impact SectorEnvironment
Broad Research Categories Exposure
Generation, Dispersion, Transformation etc.
NNI identifier

Funding Information

Anticipated Total Funding$131,961.00
Annual Funding$43,987.00
Funding SourceSwiss National Science Foundation
Funding Mechanism
Funding Sector
Start Year2007
Anticipated End Year2010


The forecasted increase in the manufacture and use of nanoparticles makes it likely that increasing human and environmental exposure will occur, and as a result, nanoparticles are beginning to come under scrutiny. Assessing the risks of nanomaterials in commercial products and environmental applications requires a better understanding of their mobility, bioavailability, and toxicity. For nanomaterials to present a risk, there must be both a potential for exposure and a hazard that results after exposure. In natural waters, nanoparticles have to be present in “solubilized” form because otherwise they will aggregate and flocculate and are removed (e.g. during wastewater treatment) or are retained in soil or groundwater. Both mobility and bioavailability depend therefore on the state of solubilization. The carbon-based fullerenes and carbon nanotubes (CNT) are an important group of novel nanoparticles. Pristine fullerenes and CNT are virtually insoluble in water and do not form stable suspensions. However, they can be solubilized by formation of clusters (fullerenes) or by addition of polymers (e.g. proteins and polysaccharides) or detergents. We hypothesize that natural polymers which are always present in waters (e.g. humic and fulvic acids) are able to solubilize CNT and fullerenes.Nanoparticles discharged with wastewater from a production facility or from households are inevitably in contact with anthropogenic detergents. We hypothesize that low concentrations of anthropogenic detergents in wastewater have a solubilizing effect on the particles. We also hypothesize that biosurfactants exuded by plants or microorganisms present in natural waters or soil solution are able to solubilize CNT and fullerenes. The solubilization will be studied by bringing fullerenes and CNT in contact with biopolymers, detergents and biosurfactants in aqueous solution and measuring the formation of solubilized, non-aggregated nanoparticles. Solubilization will be followed over time, as function of pH, background ions, and metals, and in various natural waters of different composition. Separation between solubilized and aggregated particles will be done by filtration (fullerenes) or centrifugation (CNT). Analysis of solubilized particles will be performed by UV/Vis, fluorescence or HPLC. The results from this project will yield basic information on the possibility that fullerenes and CNT can be solubilized under natural conditions